The development of new, renewable sources of transportation fuel is necessary to meet continuing demand in the face of dwindling petroleum supplies while also curbing the release of greenhouse gases. While much focus has been placed on developing biomass-derived gasoline alternatives such as ethanol and other short-chain alcohols, higher energy density distillates such as diesel and jet fuel are required for the heavy transportation sector. Furthermore, diesel engines improve fuel efficiency in small passenger vehicles over gasoline engines, and have already been widely adopted in Europe.
Biofuels such as biodiesel are biodegradable, clean-burning combustible fuels made of medium- to long-chain alkanes and esters. Biodiesel can be used in most internal combustion diesel engines in either a pure form, which is referred to as “neat” biodiesel, or as a mix in any concentration with regular petroleum diesel. An advantage of biodiesel is that it can be generated from non-petroleum sources. Current methods of making biodiesel involve transesterification of triacylglycerides (mainly vegetable oil). However, this leads to a mixture of fatty acid esters and the unwanted side product glycerin, thus, providing a product that is heterogeneous and a waste product that causes economic inefficiencies. In addition, the presence of methyl esters and ethyl esters in traditional biodiesel leads to unwanted gelation properties at or around about 0° C. There exists a need for a source of medium- to long-chain hydrocarbons that does not result in a high concentration of unwanted side products such as glycerin, methyl esters, and ethyl esters.